Motion control of steel sheet shears with rocking knife mechanism

The paper deals with development and realisation of the motion control for a very precise mechanism of a rocking knife driven by an electrical drive. The rocking knife provides transversal cutting of a moving steel strip into flat sheets of various, adjustable lengths. After development of mathematical model of the controlled mechanism there is designed the trajectory of the mechanism and based on this, a control law for the electrical drive is derived. The correctness of the design has been verified on a real mechanism in a hot rolling mill plant.